Toward a systematic 1/d expansion: Two-particle properties

We present a procedure to calculate 1/d corrections to two-particle propert ies around the infinite-dimensional dynamical mean-field limit. Our method is based on a modified version of the scheme of Schiller and Ingersent (Ref . 7), where the cancellation of overcounted diagrams is assured at each ite ration step. We test our method on the half-filled Hubbard model using the fluctuation exchange approximation. To within numerical accuracy, we find s table, causal solutions for which 1/d corrections to the local correction a re relatively small.